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Workaround/Fix for CONC-424:
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1) In case a cursor is used in a stored procedure server sends a SERVER_STATUS_CURSOR_EXISTS flag,
even if the client didn't open a cursor via mysql_stmt_attr_set. This ends in a "comands out of sync" error,
since the client is sending a COM_STMT_FETCH command while the result sets were not read before.
We check now in case server sends a SERVER_STATUS_CURSOR_EXIST flag, if the client opened a cursor before.

2) The stmt error codes weren't update for all COM_STMT* commands correctly, e.g. COM_STMT_FETCH didn't show an error even if it failed.
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@9EOR9
9EOR9 committed Jun 30, 2019
1 parent a0d2974 commit d09ac51
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Showing 2 changed files with 84 additions and 10 deletions.
25 changes: 15 additions & 10 deletions libmariadb/mariadb_stmt.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -56,6 +56,9 @@
#include <mysql/client_plugin.h>
#include <ma_common.h>

#define UPDATE_STMT_ERROR(stmt)\
SET_CLIENT_STMT_ERROR((stmt), (stmt)->mysql->net.last_errno, (stmt)->mysql->net.sqlstate, (stmt)->mysql->net.last_error)

#define STMT_NUM_OFS(type, a,r) ((type *)(a))[r]
#define MADB_RESET_ERROR 1
#define MADB_RESET_LONGDATA 2
Expand Down Expand Up @@ -310,7 +313,10 @@ static int stmt_cursor_fetch(MYSQL_STMT *stmt, uchar **row)
int4store(buf + STMT_ID_LENGTH, stmt->prefetch_rows);

if (stmt->mysql->methods->db_command(stmt->mysql, COM_STMT_FETCH, (char *)buf, sizeof(buf), 1, stmt))
{
UPDATE_STMT_ERROR(stmt);
return(1);
}

/* free previously allocated buffer */
ma_free_root(&result->alloc, MYF(MY_KEEP_PREALLOC));
Expand Down Expand Up @@ -1327,7 +1333,7 @@ static my_bool net_stmt_close(MYSQL_STMT *stmt, my_bool remove)
if (stmt->mysql->methods->db_command(stmt->mysql,COM_STMT_CLOSE, stmt_id,
sizeof(stmt_id), 1, stmt))
{
SET_CLIENT_STMT_ERROR(stmt, stmt->mysql->net.last_errno, stmt->mysql->net.sqlstate, stmt->mysql->net.last_error);
UPDATE_STMT_ERROR(stmt);
return 1;
}
}
Expand Down Expand Up @@ -1671,8 +1677,7 @@ int STDCALL mysql_stmt_prepare(MYSQL_STMT *stmt, const char *query, unsigned lon

fail:
stmt->state= MYSQL_STMT_INITTED;
SET_CLIENT_STMT_ERROR(stmt, mysql->net.last_errno, mysql->net.sqlstate,
mysql->net.last_error);
UPDATE_STMT_ERROR(stmt);
return(rc);
}

Expand Down Expand Up @@ -1886,7 +1891,8 @@ int stmt_read_execute_response(MYSQL_STMT *stmt)
}
}

if (stmt->upsert_status.server_status & SERVER_STATUS_CURSOR_EXISTS)
if ((stmt->upsert_status.server_status & SERVER_STATUS_CURSOR_EXISTS) &&
(stmt->flags & CURSOR_TYPE_READ_ONLY))
{
stmt->cursor_exists = TRUE;
mysql->status = MYSQL_STATUS_READY;
Expand Down Expand Up @@ -2006,8 +2012,7 @@ int STDCALL mysql_stmt_execute(MYSQL_STMT *stmt)

if (ret)
{
SET_CLIENT_STMT_ERROR(stmt, mysql->net.last_errno, mysql->net.sqlstate,
mysql->net.last_error);
UPDATE_STMT_ERROR(stmt);
return(1);
}

Expand Down Expand Up @@ -2078,8 +2083,7 @@ static my_bool madb_reset_stmt(MYSQL_STMT *stmt, unsigned int flags)
if ((ret= stmt->mysql->methods->db_command(mysql,COM_STMT_RESET, (char *)cmd_buf,
sizeof(cmd_buf), 0, stmt)))
{
SET_CLIENT_STMT_ERROR(stmt, mysql->net.last_errno, mysql->net.sqlstate,
mysql->net.last_error);
UPDATE_STMT_ERROR(stmt);
return(ret);
}
}
Expand Down Expand Up @@ -2231,6 +2235,8 @@ my_bool STDCALL mysql_stmt_send_long_data(MYSQL_STMT *stmt, uint param_number,
stmt->params[param_number].long_data_used= 1;
ret= stmt->mysql->methods->db_command(stmt->mysql, COM_STMT_SEND_LONG_DATA,
(char *)cmd_buff, packet_len, 1, stmt);
if (ret)
UPDATE_STMT_ERROR(stmt);
free(cmd_buff);
return(ret);
}
Expand Down Expand Up @@ -2441,8 +2447,7 @@ int STDCALL mariadb_stmt_execute_direct(MYSQL_STMT *stmt,
fail:
/* check if we need to set error message */
if (!mysql_stmt_errno(stmt))
SET_CLIENT_STMT_ERROR(stmt, mysql->net.last_errno, mysql->net.sqlstate,
mysql->net.last_error);
UPDATE_STMT_ERROR(stmt);
do {
stmt->mysql->methods->db_stmt_flush_unbuffered(stmt);
} while(mysql_stmt_more_results(stmt));
Expand Down
69 changes: 69 additions & 0 deletions unittest/libmariadb/ps_bugs.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -5042,8 +5042,77 @@ static int test_zerofill_1byte(MYSQL *mysql)
return OK;
}

static int test_conc424(MYSQL *mysql)
{
int rc;
MYSQL_STMT *stmt;
my_bool max_len= 1;

rc= mysql_query(mysql, "DROP TABLE IF EXISTS test_table1");
check_mysql_rc(rc, mysql);
rc= mysql_query(mysql, "CREATE TABLE test_table1 (test_int INT, b int)");
check_mysql_rc(rc, mysql);
rc= mysql_query(mysql, "INSERT INTO test_table1 values(10,11),(11,12)");
check_mysql_rc(rc, mysql);

rc= mysql_query(mysql, "DROP PROCEDURE IF EXISTS testCursor");
check_mysql_rc(rc, mysql);

rc= mysql_query(mysql, "CREATE PROCEDURE testCursor()\n"
"BEGIN\n"
"DECLARE test_int INT;\n"
"DECLARE b INT;\n"
"DECLARE done INT DEFAULT FALSE;\n"
"DECLARE testCursor CURSOR\n"
"FOR\n"
"SELECT test_int,b FROM test_table1;\n"
"DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;\n"
"OPEN testCursor;\n"

" read_loop: LOOP\n"
" FETCH testCursor INTO test_int, b;\n"
" IF done THEN\n"
" LEAVE read_loop;\n"
" END IF;\n"
" SELECT test_int,b;"
" END LOOP;\n"
"CLOSE testCursor;\n"
"END");
check_mysql_rc(rc, mysql);

stmt= mysql_stmt_init(mysql);
rc= mysql_stmt_prepare(stmt, SL("CALL testCursor()"));
check_stmt_rc(rc, stmt);

rc= mysql_stmt_attr_set(stmt, STMT_ATTR_UPDATE_MAX_LENGTH, &max_len);
check_stmt_rc(rc, stmt);

rc= mysql_stmt_execute(stmt);
check_stmt_rc(rc, stmt);

do {
if (mysql_stmt_field_count(stmt))
{
MYSQL_RES *res= mysql_stmt_result_metadata(stmt);
rc= mysql_stmt_fetch(stmt);
FAIL_IF(rc, "Wrong return code");
mysql_free_result(res);
}
rc= mysql_stmt_next_result(stmt);

} while (!rc);

rc= mysql_query(mysql, "DROP PROCEDURE testCursor");
check_mysql_rc(rc, mysql);

rc= mysql_query(mysql, "DROP TABLE test_table1");
check_mysql_rc(rc, mysql);

return OK;
}

struct my_tests_st my_tests[] = {
{"test_conc424", test_conc424, TEST_CONNECTION_NEW, 0, NULL, NULL},
{"test_conc344", test_conc344, TEST_CONNECTION_NEW, 0, NULL, NULL},
{"test_conc334", test_conc334, TEST_CONNECTION_NEW, 0, NULL, NULL},
{"test_compress", test_compress, TEST_CONNECTION_NEW, CLIENT_COMPRESS, NULL, NULL},
Expand Down

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